This document specifies the test method for the determination of the deviation from a flat image surface, i.e. the sagittal and tangential field curvature of telescopic systems and observational telescopic instruments.Cross References:ISO 14490-1:2005ISO 14132-1ISO 10934-1:2002ISO 20473ISO 14490-7All current amendments available at time of purchase are included with the purchase of this document.